Catheters may be used for introducing and removing fluids in and from various vessels and cavities throughout the body. Central venous catheters, for example, are generally placed in four common locations within the chest and/or in the femoral vessels. They may be placed, for example, in either the right or left subclavian vein or in the right or left internal jugular vein. Such catheters are largely introduced in accordance with the known Seldinger technique, which involves use of a guide wire to properly place the catheter in the catheterized area.
Using landmarks, vessels are identified and may be cannulated by first aspirating the vessel with a long hollow needle, which may be attached to a syringe or other aspirating device to ensure that the vessel has been properly located. When the vessel has been properly located and aspirated, if a syringe is used, the syringe is disconnected and a thin guide wire is passed through the needle into the hollow passage, or lumen, of the vessel. Other introducers allow the guide wire to pass through the syringe or device without removing the device from the needle. The needle or other introducer device is then removed, leaving one end of the guide wire within the vessel. The other end of the guide wire projects beyond the surface of the skin.
At this point, the simplest method of catheter placement is to pass a catheter into the vessel directly over the guide wire. The guide wire is then removed, leaving the catheter in position within the vessel. The catheter as placed can then function in various applications such as infusion, perfusion, hemodialysis and the like.
The guide wires used for such procedures are generally spring wires which typically have a curved J-shaped tip. The nature of the spring wire, which is typically constructed from a memory alloy, causes the tip to return to the J-shape after applied stress is removed. Therefore, in order to slide the tip through the device and to keep the wire from bending back on itself while entering the patient, such wires are typically introduced through a straightening device. The guide wire has a relatively long length. For convenience, the wire is typically packaged and used as a coil. The coils generally have plastic clips which help to hold the coil together for handling. In addition, the coils can be packaged in protective storage tubes which also may use clips to hold the tubes in a coiled configuration.
The primary cost incurred in preparing catheter and catheter introducer kits are the catheters, wires and needles. Other accessories and components which facilitate catheter introduction are also included in such kits. However, in preparing such kits, manufacturers must balance the objectives of making such kits as easy to use and as complete as possible for medical personnel against the objective of providing a commercially acceptable cost for such kits. One method of minimizing overall cost is to minimize the cost of the accessory items. The kits typically include a catheter, a guide wire, a guide wire straightener and/or feeding mechanism, an introducer and/or needle, a scalpel, connectors and various other related instruments for introducing the catheter into a patient. In addition, the accessory items may be packaged alone as an introducer kit which is sold separately from an individual catheter, or as a combined catheter and introducer kit which includes a specific catheter and its associated accessories. As such, there is a need in the art to provide accessories which are cost effective to manufacture and which do not significantly increase the cost of the kit, but which are effective in facilitating insertion of the guide wire and catheter.
As discussed further below, there are various devices available for advancing a guide wire through an introducer, such as a needle, into a patient. However, there is an on-going need in the art to improve upon such guide wire advancers with the objective of reducing their cost of manufacture to reduce the overall cost of introducer and catheter kits, while maintaining and/or improving their effectiveness in advancing a guide wire into a patient as well as making them easier to use and manipulate as discussed below.
In addition to the manufacturing cost objective noted above, the mechanical difficulties encountered by a physician or other medical personnel using such guide wires typically are the result of the need to use two hands to handle the guide wire and to operate an advancing apparatus while inserting the guide wire through the needle into the patient. Various prior art devices are directed to simplifying the advancing and insertion procedure, including a plastic cone having a hole at the tip of the cone for passing the guide wire through the hole into the introducer hub, and a shuttling device as described in U.S. Pat. No. 4,713,059. These devices, while assisting in advancing the wire through the introducer and guiding the wire into the needle, require two hands to operate.
Syringes have been adapted which advance and straighten the wire and pass the wire through the syringe directly into the needle without detaching the syringe. While such devices minimize bleeding, they are highly specialized and complex with respect to the central passages and valves within the syringe, and occasionally, difficulty is still encountered in feeding the guide wire into the end of the syringe, requiring a peripheral straightening device. Due to the more complex nature of such syringes, while they may improve effectiveness in handling the guide wire, they are relatively expensive to manufacture. Examples of guide wire introducing syringes may be found in U.S. Pat. Nos. 4,274,408, 4,417,886, 4,813,938, and 5,045,065.
Other solutions to the problem of two-handed guide wire advancing and straightening include a device as described in U.S. Pat. No. 5,125,906, which teaches a trigger-like handle with a clip which can be attached to a guide wire feeding tube or coil. The device has a frustoconical, tapered, distal end portion. The device is held with the fingers coiled around the trigger handle and the guide wire is fed into the device through a proximal opening, slid across a flat surface by the thumb and through the distal end portion into a syringe or needle introducer. A modified version of the device is disclosed in U.S. Pat. No. 5,484,419, which includes an additional, separate conical end fitting which can be placed over the end portion to help feed the guide wire into the needle and which has an arched underneath surface for facilitating handling of the device to enhance sliding of the guide wire over a flat top surface of the device.
A virtually identical device is described in U.S. Pat. No. 5,507,300, which provides a rubber band along the wire guide to allow the physician to stop the insertion of the guide wire without letting the guide wire slip along the guide.
U.S. Pat. No. 5,366,444 discloses a guide wire advancer which provides a head with a guide opening, a discharge opening, and an open platform therebetween. A guide wire is advanced over the platform with a thumb, with a forefinger engaging a depression on an underside of the platform.
Other devices disclosed by U.S. Pat. Nos. 4,860,757, 4,917,094, 5,273,042, 5,438,993, and 5,448,993 describe a guide wire housed in a tube with apertures or a conical straightener as described above with a thumb opening cut into the conical portion. A physician""s thumb fits into the aperture to engage the guide wire to advance or retract the guide wire through the tube.
The above-described guide wire straighteners assert one-handed operation of the device to introduce the guide wire into the needle. However, problems may still be encountered in holding the tip of the straightening or advancing device firmly within the needle fitting while introducing the guide wire into the needle to avoid slipping of the device out of the needle while advancing the guide wire across the device with the physician""s thumb. Further, the physician is generally wearing rubber gloves, which reduce the tactile sensation of the thumb as the thumb operates the guide wire. In addition, it would be advantageous to further reduce the cost of making such guide wire advancing devices and thereby reduce the overall cost of introducer kits and catheter kits which include the straightener and feeding devices and other accessories.
Therefore, there is a need in the art for a guide wire advancer and/or straightening device which is cost effective to manufacture and which minimizes the overall cost of introducer kits and catheter kits incorporating the device. There is also a need for such a device which is easy to operate with only one hand, which does not slip from the needle fitting during the guide wire advancing procedure such that additional stability in handling can be achieved and which provides greater tactile feel to the user for controlling the rate of advancement of the wire into the patient. There is further a need in the art for such an advancing device which advances easily into a guide wire feeding tube while still firmly gripping the tube once inserted. The present invention satisfies such needs.
In one aspect, the present invention is a guide wire advancer which comprises a distal portion having a passageway extending longitudinally therethrough, the distal portion being capable of straightening a guide wire; a proximal portion having a passageway extending longitudinally therethrough; and a central portion having first and second members which extend between the distal portion and the proximal portion. The first and second members define an opening therebetween to provide access for a user""s thumb and finger to advance the guide wire through the advancer.
In another aspect, the present invention is a guide wire advancer assembly which comprises a guide wire assembly comprising a distal portion having a passageway extending longitudinally therethrough, and which is capable of straightening a guide wire; a proximal portion having a passageway extending longitudinally therethrough; a central portion having first and second members which extend between the distal portion and the proximal portion, the first and second members defining an opening therebetween to provide access for a user""s thumb and finger to advance the guide wire through the advancer; and a guide wire storage tube having an outer diameter being substantially the same as an inner diameter of the proximal portion.
Also includes in the invention is a method for using an advancer. The advancer in the method comprises a distal portion having a passageway extending longitudinally therethrough and having an exterior surface; a proximal portion having a passageway extending longitudinally therethrough; and a central portion having first and second members extending between the distal portion and the proximal portion. The first and second members define an opening capable of providing access for a user""s thumb and finger. The method comprises the steps of inserting a distal portion of the advancer into a proximal end of a guide wire introducer; passing an end of the guide wire through the proximal portion of the advancer; and feeding the guide wire through the advancer using a thumb and a finger in the opening in the central portion such that the end of the guide wire passes through the passageway in the distal portion of the advancer, through the guide wire introducer, and into a patient.